24 files changed, 104 insertions, 6 deletions

diff --git a/arch/alpha/include/asm/socket.h b/arch/alpha/include/asm/socket.h
index 16449d330dae..dcb221a4b5be 100644
--- a/arch/alpha/include/asm/socket.h
+++ b/arch/alpha/include/asm/socket.h
@@ -73,6 +73,9 @@
 #define SCM_WIFI_STATUS         SO_WIFI_STATUS
 #define SO_PEEK_OFF             42
 
+/* Instruct lower device to use last 4-bytes of skb data as FCS */
+#define SO_NOFCS                43
+
 /* O_NONBLOCK clashes with the bits used for socket types.  Therefore we
  * have to define SOCK_NONBLOCK to a different value here.
  */
diff --git a/arch/arm/include/asm/socket.h b/arch/arm/include/asm/socket.h
index d958c74e5260..6433cadb6ed4 100644
--- a/arch/arm/include/asm/socket.h
+++ b/arch/arm/include/asm/socket.h
@@ -66,4 +66,7 @@
 #define SCM_WIFI_STATUS         SO_WIFI_STATUS
 #define SO_PEEK_OFF             42
 
+/* Instruct lower device to use last 4-bytes of skb data as FCS */
+#define SO_NOFCS                43
+
 #endif /* _ASM_SOCKET_H */
diff --git a/arch/avr32/include/asm/socket.h b/arch/avr32/include/asm/socket.h
index 30078f98b3ab..a473f8c6a9aa 100644
--- a/arch/avr32/include/asm/socket.h
+++ b/arch/avr32/include/asm/socket.h
@@ -66,4 +66,7 @@
 #define SCM_WIFI_STATUS         SO_WIFI_STATUS
 #define SO_PEEK_OFF             42
 
+/* Instruct lower device to use last 4-bytes of skb data as FCS */
+#define SO_NOFCS                43
+
 #endif /* __ASM_AVR32_SOCKET_H */
diff --git a/arch/cris/include/asm/socket.h b/arch/cris/include/asm/socket.h
index 048aba64600c..ae52825021af 100644
--- a/arch/cris/include/asm/socket.h
+++ b/arch/cris/include/asm/socket.h
@@ -68,6 +68,9 @@
 #define SCM_WIFI_STATUS         SO_WIFI_STATUS
 #define SO_PEEK_OFF             42
 
+/* Instruct lower device to use last 4-bytes of skb data as FCS */
+#define SO_NOFCS                43
+
 #endif /* _ASM_SOCKET_H */
 
 
diff --git a/arch/frv/include/asm/socket.h b/arch/frv/include/asm/socket.h
index 7a361810f3cc..a5b1d7dbb205 100644
--- a/arch/frv/include/asm/socket.h
+++ b/arch/frv/include/asm/socket.h
@@ -66,5 +66,8 @@
 #define SCM_WIFI_STATUS         SO_WIFI_STATUS
 #define SO_PEEK_OFF             42
 
+/* Instruct lower device to use last 4-bytes of skb data as FCS */
+#define SO_NOFCS                43
+
 #endif /* _ASM_SOCKET_H */
 
diff --git a/arch/h8300/include/asm/socket.h b/arch/h8300/include/asm/socket.h
index e7bbfcee5b99..ec4554e7b04b 100644
--- a/arch/h8300/include/asm/socket.h
+++ b/arch/h8300/include/asm/socket.h
@@ -66,4 +66,7 @@
 #define SCM_WIFI_STATUS         SO_WIFI_STATUS
 #define SO_PEEK_OFF             42
 
+/* Instruct lower device to use last 4-bytes of skb data as FCS */
+#define SO_NOFCS                43
+
 #endif /* _ASM_SOCKET_H */
diff --git a/arch/ia64/include/asm/socket.h b/arch/ia64/include/asm/socket.h
index ced62de9d5a9..41fc28a4a18a 100644
--- a/arch/ia64/include/asm/socket.h
+++ b/arch/ia64/include/asm/socket.h
@@ -75,4 +75,7 @@
 #define SCM_WIFI_STATUS         SO_WIFI_STATUS
 #define SO_PEEK_OFF             42
 
+/* Instruct lower device to use last 4-bytes of skb data as FCS */
+#define SO_NOFCS                43
+
 #endif /* _ASM_IA64_SOCKET_H */
diff --git a/arch/m32r/include/asm/socket.h b/arch/m32r/include/asm/socket.h
index 696cb4c7ca4e..a15f40b52783 100644
--- a/arch/m32r/include/asm/socket.h
+++ b/arch/m32r/include/asm/socket.h
@@ -66,4 +66,7 @@
 #define SCM_WIFI_STATUS         SO_WIFI_STATUS
 #define SO_PEEK_OFF             42
 
+/* Instruct lower device to use last 4-bytes of skb data as FCS */
+#define SO_NOFCS                43
+
 #endif /* _ASM_M32R_SOCKET_H */
diff --git a/arch/m68k/include/asm/socket.h b/arch/m68k/include/asm/socket.h
index e8b41a6775f9..d1be684edf97 100644
--- a/arch/m68k/include/asm/socket.h
+++ b/arch/m68k/include/asm/socket.h
@@ -66,4 +66,7 @@
 #define SCM_WIFI_STATUS         SO_WIFI_STATUS
 #define SO_PEEK_OFF             42
 
+/* Instruct lower device to use last 4-bytes of skb data as FCS */
+#define SO_NOFCS                43
+
 #endif /* _ASM_SOCKET_H */
diff --git a/arch/mips/include/asm/socket.h b/arch/mips/include/asm/socket.h
index 52104872e9e3..a2ed6fdad4e0 100644
--- a/arch/mips/include/asm/socket.h
+++ b/arch/mips/include/asm/socket.h
@@ -86,6 +86,9 @@ To add: #define SO_REUSEPORT 0x0200	/* Allow local address and port reuse.  */
 #define SCM_WIFI_STATUS         SO_WIFI_STATUS
 #define SO_PEEK_OFF             42
 
+/* Instruct lower device to use last 4-bytes of skb data as FCS */
+#define SO_NOFCS                43
+
 #ifdef __KERNEL__
 
 /** sock_type - Socket types
diff --git a/arch/mn10300/include/asm/socket.h b/arch/mn10300/include/asm/socket.h
index 013fcc51698f..820463a484b8 100644
--- a/arch/mn10300/include/asm/socket.h
+++ b/arch/mn10300/include/asm/socket.h
@@ -66,4 +66,7 @@
 #define SCM_WIFI_STATUS         SO_WIFI_STATUS
 #define SO_PEEK_OFF             42
 
+/* Instruct lower device to use last 4-bytes of skb data as FCS */
+#define SO_NOFCS                43
+
 #endif /* _ASM_SOCKET_H */
diff --git a/arch/parisc/include/asm/socket.h b/arch/parisc/include/asm/socket.h
index f717c9bec16f..1b52c2c31a7a 100644
--- a/arch/parisc/include/asm/socket.h
+++ b/arch/parisc/include/asm/socket.h
@@ -65,6 +65,10 @@
 #define SCM_WIFI_STATUS         SO_WIFI_STATUS
 #define SO_PEEK_OFF             0x4023
 
+/* Instruct lower device to use last 4-bytes of skb data as FCS */
+#define SO_NOFCS                0x4024
+
+
 /* O_NONBLOCK clashes with the bits used for socket types.  Therefore we
  * have to define SOCK_NONBLOCK to a different value here.
  */
diff --git a/arch/powerpc/include/asm/socket.h b/arch/powerpc/include/asm/socket.h
index fe1c0b478fd7..3d5179bb122f 100644
--- a/arch/powerpc/include/asm/socket.h
+++ b/arch/powerpc/include/asm/socket.h
@@ -73,4 +73,7 @@
 #define SCM_WIFI_STATUS         SO_WIFI_STATUS
 #define SO_PEEK_OFF             42
 
+/* Instruct lower device to use last 4-bytes of skb data as FCS */
+#define SO_NOFCS                43
+
 #endif  /* _ASM_POWERPC_SOCKET_H */
diff --git a/arch/s390/include/asm/socket.h b/arch/s390/include/asm/socket.h
index 581702fa1b0c..c91b720965c0 100644
--- a/arch/s390/include/asm/socket.h
+++ b/arch/s390/include/asm/socket.h
@@ -74,4 +74,7 @@
 #define SCM_WIFI_STATUS         SO_WIFI_STATUS
 #define SO_PEEK_OFF             42
 
+/* Instruct lower device to use last 4-bytes of skb data as FCS */
+#define SO_NOFCS                43
+
 #endif /* _ASM_SOCKET_H */
diff --git a/arch/sparc/include/asm/socket.h b/arch/sparc/include/asm/socket.h
index 68e2e2746f6f..bea1568ae4af 100644
--- a/arch/sparc/include/asm/socket.h
+++ b/arch/sparc/include/asm/socket.h
@@ -62,6 +62,10 @@
 #define SCM_WIFI_STATUS         SO_WIFI_STATUS
 #define SO_PEEK_OFF             0x0026
 
+/* Instruct lower device to use last 4-bytes of skb data as FCS */
+#define SO_NOFCS                0x0027
+
+
 /* Security levels - as per NRL IPv6 - don't actually do anything */
 #define SO_SECURITY_AUTHENTICATION              0x5001
 #define SO_SECURITY_ENCRYPTION_TRANSPORT        0x5002
diff --git a/arch/xtensa/include/asm/socket.h b/arch/xtensa/include/asm/socket.h
index 74818b161362..e36c68184920 100644
--- a/arch/xtensa/include/asm/socket.h
+++ b/arch/xtensa/include/asm/socket.h
@@ -77,4 +77,7 @@
 #define SCM_WIFI_STATUS         SO_WIFI_STATUS
 #define SO_PEEK_OFF             42
 
+/* Instruct lower device to use last 4-bytes of skb data as FCS */
+#define SO_NOFCS                43
+
 #endif  /* _XTENSA_SOCKET_H */
diff --git a/include/asm-generic/socket.h b/include/asm-generic/socket.h
index d9aaac0c36d4..b1bea03274d5 100644
--- a/include/asm-generic/socket.h
+++ b/include/asm-generic/socket.h
@@ -68,4 +68,8 @@
 #define SO_WIFI_STATUS          41
 #define SCM_WIFI_STATUS SO_WIFI_STATUS
 #define SO_PEEK_OFF             42
+
+/* Instruct lower device to use last 4-bytes of skb data as FCS */
+#define SO_NOFCS                43
+
 #endif /* __ASM_GENERIC_SOCKET_H */
diff --git a/include/linux/if.h b/include/linux/if.h
index 06b6ef60c821..f995c663c493 100644
--- a/include/linux/if.h
+++ b/include/linux/if.h
@@ -80,6 +80,8 @@
                                          * skbs on transmit */
 #define IFF_UNICAST_FLT 0x20000         /* Supports unicast filtering   */
 #define IFF_TEAM_PORT   0x40000         /* device used as team port */
+#define IFF_SUPP_NOFCS  0x80000         /* device supports sending custom FCS */
+
 
 #define IF_GET_IFACE    0x0001          /* for querying only */
 #define IF_GET_PROTO    0x0002
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 0eac07c95255..f1b7d037c2c5 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1082,7 +1082,8 @@ struct net_device {
         const struct header_ops *header_ops;
 
         unsigned int            flags;  /* interface flags (a la BSD)   */
-        unsigned int            priv_flags; /* Like 'flags' but invisible to userspace. */
+        unsigned int            priv_flags; /* Like 'flags' but invisible to userspace.
+                                             * See if.h for definitions. */
         unsigned short          gflags;
         unsigned short          padded; /* How much padding added by alloc_netdev() */
 
@@ -2650,6 +2651,11 @@ static inline int netif_is_bond_slave(struct net_device *dev)
         return dev->flags & IFF_SLAVE && dev->priv_flags & IFF_BONDING;
 }
 
+static inline bool netif_supports_nofcs(struct net_device *dev)
+{
+        return dev->priv_flags & IFF_SUPP_NOFCS;
+}
+
 extern struct pernet_operations __net_initdata loopback_net_ops;
 
 /* Logging, debugging and troubleshooting/diagnostic helpers. */
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index c11a44ea1bf4..06a4c0fd7bef 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -361,6 +361,7 @@ typedef unsigned char *sk_buff_data_t;
  *              ports.
  *      @wifi_acked_valid: wifi_acked was set
  *      @wifi_acked: whether frame was acked on wifi or not
+ *      @no_fcs:  Request NIC to treat last 4 bytes as Ethernet FCS
  *      @dma_cookie: a cookie to one of several possible DMA operations
  *              done by skb DMA functions
  *      @secmark: security marking
@@ -459,7 +460,8 @@ struct sk_buff {
         __u8                    l4_rxhash:1;
         __u8                    wifi_acked_valid:1;
         __u8                    wifi_acked:1;
-        /* 10/12 bit hole (depending on ndisc_nodetype presence) */
+        __u8                    no_fcs:1;
+        /* 9/11 bit hole (depending on ndisc_nodetype presence) */
         kmemcheck_bitfield_end(flags2);
 
 #ifdef CONFIG_NET_DMA
diff --git a/include/net/sock.h b/include/net/sock.h
index 9c0553b9e451..ba761e7de252 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -615,6 +615,10 @@ enum sock_flags {
         SOCK_RXQ_OVFL,
         SOCK_ZEROCOPY, /* buffers from userspace */
         SOCK_WIFI_STATUS, /* push wifi status to userspace */
+        SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
+                     * Will use last 4 bytes of packet sent from
+                     * user-space instead.
+                     */
 };
 
 static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index f3a530780753..6eb656acdfe5 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -592,6 +592,7 @@ static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
         new->rxhash             = old->rxhash;
         new->ooo_okay           = old->ooo_okay;
         new->l4_rxhash          = old->l4_rxhash;
+        new->no_fcs             = old->no_fcs;
 #ifdef CONFIG_XFRM
         new->sp                 = secpath_get(old->sp);
 #endif
diff --git a/net/core/sock.c b/net/core/sock.c
index 19942d4bb6e6..55011cb691ad 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -799,6 +799,11 @@ set_rcvbuf:
                 else
                         ret = -EOPNOTSUPP;
                 break;
+
+        case SO_NOFCS:
+                sock_valbool_flag(sk, SOCK_NOFCS, valbool);
+                break;
+
         default:
                 ret = -ENOPROTOOPT;
                 break;
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 2dbb32b988c4..ae2d484416dd 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1459,6 +1459,7 @@ static int packet_sendmsg_spkt(struct kiocb *iocb, struct socket *sock,
         struct net_device *dev;
         __be16 proto = 0;
         int err;
+        int extra_len = 0;
 
         /*
          *      Get and verify the address.
@@ -1493,8 +1494,16 @@ retry:
          * raw protocol and you must do your own fragmentation at this level.
          */
 
+        if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
+                if (!netif_supports_nofcs(dev)) {
+                        err = -EPROTONOSUPPORT;
+                        goto out_unlock;
+                }
+                extra_len = 4; /* We're doing our own CRC */
+        }
+
         err = -EMSGSIZE;
-        if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN)
+        if (len > dev->mtu + dev->hard_header_len + VLAN_HLEN + extra_len)
                 goto out_unlock;
 
         if (!skb) {
@@ -1526,7 +1535,7 @@ retry:
                 goto retry;
         }
 
-        if (len > (dev->mtu + dev->hard_header_len)) {
+        if (len > (dev->mtu + dev->hard_header_len + extra_len)) {
                 /* Earlier code assumed this would be a VLAN pkt,
                  * double-check this now that we have the actual
                  * packet in hand.
@@ -1548,6 +1557,9 @@ retry:
         if (err < 0)
                 goto out_unlock;
 
+        if (unlikely(extra_len == 4))
+                skb->no_fcs = 1;
+
         dev_queue_xmit(skb);
         rcu_read_unlock();
         return len;
@@ -2209,6 +2221,7 @@ static int packet_snd(struct socket *sock,
         struct packet_sock *po = pkt_sk(sk);
         unsigned short gso_type = 0;
         int hlen, tlen;
+        int extra_len = 0;
 
         /*
          *      Get and verify the address.
@@ -2288,8 +2301,16 @@ static int packet_snd(struct socket *sock,
                 }
         }
 
+        if (unlikely(sock_flag(sk, SOCK_NOFCS))) {
+                if (!netif_supports_nofcs(dev)) {
+                        err = -EPROTONOSUPPORT;
+                        goto out_unlock;
+                }
+                extra_len = 4; /* We're doing our own CRC */
+        }
+
         err = -EMSGSIZE;
-        if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN))
+        if (!gso_type && (len > dev->mtu + reserve + VLAN_HLEN + extra_len))
                 goto out_unlock;
 
         err = -ENOBUFS;
@@ -2315,7 +2336,7 @@ static int packet_snd(struct socket *sock,
         if (err < 0)
                 goto out_free;
 
-        if (!gso_type && (len > dev->mtu + reserve)) {
+        if (!gso_type && (len > dev->mtu + reserve + extra_len)) {
                 /* Earlier code assumed this would be a VLAN pkt,
                  * double-check this now that we have the actual
                  * packet in hand.
@@ -2353,6 +2374,9 @@ static int packet_snd(struct socket *sock,
                 len += vnet_hdr_len;
         }
 
+        if (unlikely(extra_len == 4))
+                skb->no_fcs = 1;
+
         /*
          *      Now send it
          */